562 research outputs found

    Malformações do desenvolvimento cortical: conceitos atuais e revisão de neuro-imagem avançada

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    Malformations of cortical development (MCD) result from disruptions in the complex process of the human brain cortex formation and are highly associated to severe epilepsy, neurodevelopmental delay and motor dysfunction. Nowadays, magnetic resonance imaging (MRI) is the cornerstone of the work-up of patients with epilepsy and modern advanced imaging techniques have improved not only our ability to detect and characterize cortical malformations, but also in identifying associated functional abnormalities that are far beyond the structural visualized lesions. Herein, we address the most currently used classifications of MCD and make a concise review of the embryological process of cortical development. Our main goal is to summarize recent advances and new trends in diagnostic imaging techniques concerning MCD. Thereafter, follows a brief discussion of specific disorders and their radiological features.As malformações do desenvolvimento cortical (MDC) resultam de distúrbios no complexo processo do desenvolvimento do córtex cerebral humano e estão comumente associadas a epilepsia severa e disfunções neuropsicomotoras. Atualmente, as imagens por ressonância magnética (RM) são a pedra angular no manejo de pacientes com epilepsia e modernas técnicas avançadas de imagem melhoraram não só a nossa capacidade de detectar e caracterizar as malformações corticais, mas também levaram ao reconhecimento de anomalias funcionais associadas que estão muito além das lesões estruturais visibilizadas. Abordaremos as classificações mais utilizadas de MDC e revisaremos a embriologia do desenvolvimento cortical. Nosso principal objetivo é destacar os avanços recentes e as novas tendências em técnicas de diagnóstico por imagens relacionadas às MDC. Em seguida, faremos uma breve discussão sobre alguns transtornos específicos e suas características radiológicas.FAPESPCNP

    Avaliação da eficácia, segurança e tolerabilidade da sibutramina em obesos - estudo randomizado duplo-cego

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    This is a double-blind, placebo-controlled study of the efficacy, safety, and tolerability of sibutramine in the management of obese patients for a 6-month period. METHOD: Sixty-one obese patients (BMI >;30, ;5% in 40% of the patients on sibutramine compared with 12.9% in the placebo group. We also detected weight gain in 45.2% of the placebo group compared to 20% in the sibutramine group. The sibutramine group showed improvement in HDL- cholesterol values (increased by 17%) and triglyceride values (decreased by 12.8%). This group also showed an increase in systolic blood pressure (6.7%, 5 mmHg). There were no changes in echocardiograms comparing the beginning and end of follow-up, and side effects did not lead to discontinuation of treatment. DISCUSSION: Sibutramine proved to be effective for weight loss providing an 8% loss of the initial weight. Compliance to prolonged treatment was good, and side effects did not result in discontinuation of treatment. These data confirmed the good efficacy, tolerability, and safety profiles of sibutramine for treatment of obesity.O presente estudo objetivou comparar a eficácia, segurança e tolerabilidade da sibutramina em pacientes obesos. MÉTODO: Selecionamos 61 pacientes obesos (3

    Dimensões da faringe em homens e mulheres saudáveis

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    INTRODUCTION: Epidemiological studies reveal a high male prevalence of obstructive sleep apnea syndrome. A possible explanation for this male predominance is the existence of anatomical differences in the upper airway between men and women. METHODS: The upper airways of 10 male and 10 female healthy volunteers were prospectively evaluated by magnetic resonance imaging. Anatomical pharyngeal and column cross-sectional linear measurements were made in sagittal T1 and axial T1 and T2 weighted fast spin-echo images. RESULTS: Men had significantly greater mean sagittal pharyngeal structural dimensions compared to women for all structures with the exception of the craniocaudal length of the soft palate and the thickness of the submentonian fat. In contrast, cross-sectional linear dimensions were similar in men and women with the exception of the laterolateral tongue length, which was greater in men. All mean linear measurements of the pharyngeal air column were similar in men and women at all studied levels. CONCLUSIONS: Men and women present pharyngeal air columns with similar dimensions, but in women this column is surrounded by smaller structures, which might imply a smaller effort to keep its patency. Our data suggest the existence of an anatomical protective factor in women against the upper airway collapse.INTRODUÇÃO: Estudos epidemiológicos demonstram alta prevalência da síndrome da apnéia obstrutiva do sono no sexo masculino. Uma explicação plausível para esta predominância masculina é a existência de diferenças anatômicas nas vias aéreas superiores entre homens e mulheres. MÉTODOS: As vias aéreas superiores de 10 homens e 10 mulheres, voluntários saudáveis, foram avaliados prospectivamente através do exame de ressonância magnética. Foram realizadas medidas lineares das vias aéreas superiores e das estruturas da faringe através de imagens sagitais pesadas em T1 e imagens axiais pesadas em T1 e T2 com a técnica de fast spin-echo. RESULTADOS: Os homens mostraram dimensões significativamente maiores das estruturas da faringe em relação às mulheres em todas as medidas realizadas nas imagens sagitais, com exceção do diâmetro crânio-caudal do palato mole e da espessura da gordura submentoniana. Em contraste, as imagens axiais mostraram medidas similares entre os sexos, exceto o diâmetro látero-lateral da língua que foi maior nos homens. Todas as medidas da coluna aérea das vias aéreas superiores foram semelhantes nos dois sexos. CONCLUSÕES: Embora homens e mulheres apresentem vias aéreas superiores com dimensões similares, nas mulheres as estruturas anatômicas ao seu redor são menores, sugerindo um menor esforço para manter as vias aéreas superiores patentes no sexo feminino. Nossos resultados sugerem a existência de um fator de proteção anatômico contra o colapso das vias aéreas superiores nas mulheres

    Priming of a DNA metabarcoding approach for species identification and inventory in marine macrobenthic communities

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    In marine and estuarine benthic communities, the inventory and estimation of species richness are often hampered by the need for broad taxonomic expertise across several phyla. The use of DNA metabarcoding has emerged as a powerful tool for the fast assessment of species composition in a diversity of ecological communities. Here, we tested the amplification success of five primer sets targeting different COI-5P regions by 454 pyrosequencing to maximize the recovery of two simulated macrobenthic communities containing 21 species (SimCom1 and SimCom 2). Species identification was first performed against a compiled reference library of macrobenthic species. Reads with similarity results to reference sequences between 70% and 97% were then submitted to GenBank and BOLD to attempt the identification of concealed species in the bulk sample. The combination of at least three primer sets was able to recover more species than any primer set alone, achieving 85% of represented species in SimCom1 and 76% in SimCom2. Our approach was successful to detect low-frequency specimens, as well as concealed species, in the bulk sample, indicating the potential for the application of this approach on marine bioassessment and inventory, including the detection of "hidden" biodiversity that would hardly be possible based on morphology only.This work was supported by FEDER through POFCCOMPETE by national funds from 'Fundacao para a Ciencia e a Tecnologia (FCT)' in the scope of the grant FCOMP-01-0124-FEDER-015429 and also by the strategic programme UID/BIA/04050/2013 (POCI-01-0145-FEDER007569). This work was also funded by national funds through the FCT I.P. and by the ERDF through the COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao (POCI). J.L. was supported by a PhD fellowship (SFRH/BD/69750/2010) from FCT and C.H. by a CAPES Post-doctoral fellowship, under Science Without Borders Program (Ministry of Education, Brazil)info:eu-repo/semantics/publishedVersio

    Segmented corpus callosum diffusivity correlates with the Expanded Disability Status Scale score in the early stages of relapsing-remitting multiple sclerosis

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    OBJECTIVE: The aim of this study was to characterize the microscopic damage to the corpus callosum in relapsing-remitting multiple sclerosis (RRMS) with diffusion tensor imaging and to investigate the correlation of this damage with disability. The diffusion tensor imaging parameters of fractional anisotropy and mean diffusivity provide information about the integrity of cell membranes, offering two more specific indices, namely the axial and radial diffusivities, which are useful for discriminating axon loss from demyelination. METHOD: Brain magnetic resonance imaging exams of 30 relapsing-remitting multiple sclerosis patients and 30 age- and sex-matched healthy controls were acquired in a 3T scanner. The axial diffusivities, radial diffusivities, fractional anisotropy, and mean diffusivity of five segments of the corpus callosum, correlated to the Expanded Disability Status Scale score, were obtained. RESULTS: All corpus callosum segments showed increased radial diffusivities and mean diffusivity, as well as decreased fractional anisotropy, in the relapsing-remitting multiple sclerosis group. The axial diffusivity was increased in the posterior midbody and splenium. The Expanded Disability Status Scale scores correlated more strongly with axial diffusivities and mean diffusivity, with an isolated correlation with radial diffusivities in the posterior midbody of the corpus callosum. There was no significant correlation with lesion loads. CONCLUSION: Neurological dysfunction in relapsing-remitting multiple sclerosis can be influenced by commissural disconnection, and the diffusion indices of diffusion tensor imaging are potential biomarkers of disability that can be assessed during follow-up
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